1. Field of the Invention
The present invention relates to, for example, a method for producing a water-insoluble liquefied fuel oil containing a hydrocarbon from biomass as a principal component, whereby the yield of the water-insoluble liquefied fuel oil is high, and a method for producing a water-insoluble liquefied fuel oil from biomass, whereby the yield of the water-insoluble liquefied fuel oil is high and the degeneration of the solvent to be used for liquefaction is low.
2. Background Art
Examples of conventional methods for producing liquefied fuel oils using biomass as a feedstock are as follows. Patent Documents 1 to 3 disclose that a liquefaction catalyst for biomass, which is potassium carbonate dissolved in water and biomass in the form of wood chips are processed at 200° C. to 385° C., thereby producing a liquefied fuel oil in a yield ranging from 23 wt % to 45 wt % based on the solid biomass content.
Patent Document 4 discloses that wood chips, water, a neutral oxygen-containing solvent (acetone, methyl ethyl ketone, ethyl acetate, 1-butanol, etc.), and potassium carbonate are processed at 300° C., thereby producing a liquefied fuel oil in a yield ranging from 33 wt % to 68 wt % based on the solid biomass content.
Patent Document 5 discloses that wood chips, water, a phenolic compound (phenol or cresol), and an alkali metal compound or alkaline earth metal compound (potassium carbonate, sodium carbonate, calcium carbonate, sodium hydroxide, calcium hydroxide, etc.) are processed at 350° C., thereby producing a liquefied fuel oil in a yield ranging from 47 wt % to 65 wt % based on the solid biomass content.
Patent Document 6 discloses that cellulosic biomass and one type of organic solvent selected from aliphatic ketones and fatty alcohols (acetone, methyl ethyl ketone, methanol, ethanol, etc.) are subjected to pyrolysis at a temperature equal to or higher than a supercritical temperature in the presence of an activated carbon catalyst, thereby producing a liquefied fuel oil in a yield of about 50 wt % based on the solid biomass content.
Patent Document 7 discloses that lignocellulosic biomass is processed with a supercritical alcohol (methanol, etc.) at 320° C. to 360° C., thereby producing a liquefied fuel oil that is alcohol-soluble in a yield of about 70 wt % based on the solid biomass content.
Patent Document 8 discloses that biomass is processed with 1-octanol at 195° C. to 500° C., thereby producing a liquefied fuel oil in a maximum yield of about 90 wt % based on the solid biomass content.
Patent Document 9 discloses that biomass is processed with a mixed solvent obtained by adding 5 vol % to 20 vol % of water to a fatty alcohol having 1 to 8 carbon atoms (methanol, etc.) under supercritical or subcritical conditions for the alcohol, thereby producing a liquefied fuel oil in a maximum yield of 95 wt % based on the solid biomass content.
Patent Document 10 discloses that ligneous biomass is processed with an organic solvent such as anthracene at 250° C. to 400° C., thereby producing a liquefied fuel oil that is soluble in acetone in a yield of 45 wt % based on the solid biomass content.
Also, the present inventors have already found and disclosed a method for producing a liquefied fuel oil, which comprises adding a solvent that contains an organic solvent and is adjusted to have a moisture percentage ranging from 10 wt % to 25 wt % (including moisture contained in the biomass) to the biomass containing lignocellulose and then performing liquefaction at a temperature between 250° C. and 350° C. (Patent Documents 11 and 12).
Non-Patent Document 1 discloses that a liquefied fuel oil obtained by pyrolysis of biomass is subjected to hydrotreating with a Co/Mo catalyst, or cracking with a zeolite catalyst, thereby producing the high-grade liquefied fuel oil.    [Patent Document 1] JP Patent No. 1653948    [Patent Document 2] JP Patent No. 1653949    [Patent Document 3] JP Patent No. 1791733    [Patent Document 4] JP Patent No. 1660994    [Patent Document 5] JP Patent No. 1688399    [Patent Document 6] JP Patent No. 1888337    [Patent Document 7] JP Patent No. 3755076    [Patent Document 8] JP Patent Publication (Kokai) No. 2005-288406 A    [Patent Document 9] JP Patent Publication (Kokai) No. 2005-296906 A    [Patent Document 10] JP Patent Publication (Kokai) No. 2006-063310 A    [Patent Document 11] International Publication WO 2009/014225 Pamphlet    [Patent Document 12] JP Patent Publication (Kokai) No. 2009-46661 A    [Non-Patent Document 1] Bridgwater, A. V., Production of high grade fuels and chemicals from catalytic pyrolysis of biomass, Catal. Today, 1996, 29 (1/4), pp. 285-295